From: Laszlo Ersek <lersek@redhat.com>
To: Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org
Cc: pbonzini@redhat.com, kwolf@redhat.com, mreitz@redhat.com,
qemu-block@nongnu.org, pkrempa@redhat.com, mst@redhat.com,
marcel.apfelbaum@gmail.com
Subject: Re: [Qemu-devel] [RFC PATCH 6/6] pc: Support firmware configuration with -blockdev
Date: Tue, 5 Mar 2019 18:08:11 +0100 [thread overview]
Message-ID: <d610dae9-9c16-9ccc-762a-79cff5ed2be8@redhat.com> (raw)
In-Reply-To: <87bm2qzfyn.fsf@dusky.pond.sub.org>
On 03/04/19 18:50, Markus Armbruster wrote:
> Alright, we can call object_get_class(dev_obj)->unparent(dev_obj).
>
> Final complication: if I call just that, the device's reference counter
> goes down to zero in the middle of device_unparent(), and we use after
> free. So I bracket he call with object_ref() and object_unref().
I don't think that requiring such a bracketing is necessarily a problem.
I vaguely remember reviewing a kernel patch 6 or so years ago where the
patch used the same idea, with those "get" and "put" functions (the bug
the patch was fixing was that the last reference was "temporarily" lost
mid-operation).
So perhaps this can be addressed, for the general case, by extending the
documentation of device_unparent(). (The function has no documentation
at all, at the moment.)
Thanks
Laszlo
next prev parent reply other threads:[~2019-03-05 17:08 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-25 18:37 [Qemu-devel] [RFC PATCH 0/6] pc: Support firmware configuration with -blockdev Markus Armbruster
2019-02-25 18:37 ` [Qemu-devel] [RFC PATCH 1/6] qdev: Fix latent bug with compat_props and onboard devices Markus Armbruster
2019-02-26 12:28 ` Marc-André Lureau
2019-02-25 18:37 ` [Qemu-devel] [RFC PATCH 2/6] qom: Move compat_props machinery from qdev to QOM Markus Armbruster
2019-02-26 12:44 ` Marc-André Lureau
2019-03-04 15:57 ` Philippe Mathieu-Daudé
2019-03-05 6:52 ` Markus Armbruster
2019-02-25 18:37 ` [Qemu-devel] [RFC PATCH 3/6] vl: Fix latent bug with -global and onboard devices Markus Armbruster
2019-02-26 12:45 ` Marc-André Lureau
2019-02-25 18:37 ` [Qemu-devel] [RFC PATCH 4/6] sysbus: Fix latent bug with " Markus Armbruster
2019-02-26 12:48 ` Marc-André Lureau
2019-03-04 16:03 ` Philippe Mathieu-Daudé
2019-03-04 18:45 ` Thomas Huth
2019-03-05 6:54 ` Markus Armbruster
2019-03-05 7:17 ` Thomas Huth
2019-02-25 18:37 ` [Qemu-devel] [RFC PATCH 5/6] vl: Create block backends before setting machine properties Markus Armbruster
2019-03-04 16:14 ` Philippe Mathieu-Daudé
2019-03-05 10:38 ` Markus Armbruster
2019-03-05 11:34 ` Philippe Mathieu-Daudé
2019-03-05 14:07 ` Markus Armbruster
2019-02-25 18:37 ` [Qemu-devel] [RFC PATCH 6/6] pc: Support firmware configuration with -blockdev Markus Armbruster
2019-02-26 9:43 ` Laszlo Ersek
2019-02-26 12:35 ` Markus Armbruster
2019-02-26 16:21 ` Laszlo Ersek
2019-03-04 17:50 ` Markus Armbruster
2019-03-05 17:08 ` Laszlo Ersek [this message]
2019-03-06 6:12 ` Markus Armbruster
2019-03-04 19:14 ` Philippe Mathieu-Daudé
2019-03-04 19:52 ` Philippe Mathieu-Daudé
2019-03-05 11:31 ` Markus Armbruster
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d610dae9-9c16-9ccc-762a-79cff5ed2be8@redhat.com \
--to=lersek@redhat.com \
--cc=armbru@redhat.com \
--cc=kwolf@redhat.com \
--cc=marcel.apfelbaum@gmail.com \
--cc=mreitz@redhat.com \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=pkrempa@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).